1 // SPDX-License-Identifier: GPL-2.0 2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 3 4 #include <media/drv-intf/saa7146_vv.h> 5 6 static u32 saa7146_i2c_func(struct i2c_adapter *adapter) 7 { 8 /* DEB_I2C("'%s'\n", adapter->name); */ 9 10 return I2C_FUNC_I2C 11 | I2C_FUNC_SMBUS_QUICK 12 | I2C_FUNC_SMBUS_READ_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE 13 | I2C_FUNC_SMBUS_READ_BYTE_DATA | I2C_FUNC_SMBUS_WRITE_BYTE_DATA; 14 } 15 16 /* this function returns the status-register of our i2c-device */ 17 static inline u32 saa7146_i2c_status(struct saa7146_dev *dev) 18 { 19 u32 iicsta = saa7146_read(dev, I2C_STATUS); 20 /* DEB_I2C("status: 0x%08x\n", iicsta); */ 21 return iicsta; 22 } 23 24 /* this function runs through the i2c-messages and prepares the data to be 25 sent through the saa7146. have a look at the specifications p. 122 ff 26 to understand this. it returns the number of u32s to send, or -1 27 in case of an error. */ 28 static int saa7146_i2c_msg_prepare(const struct i2c_msg *m, int num, __le32 *op) 29 { 30 int h1, h2; 31 int i, j, addr; 32 int mem = 0, op_count = 0; 33 34 /* first determine size of needed memory */ 35 for(i = 0; i < num; i++) { 36 mem += m[i].len + 1; 37 } 38 39 /* worst case: we need one u32 for three bytes to be send 40 plus one extra byte to address the device */ 41 mem = 1 + ((mem-1) / 3); 42 43 /* we assume that op points to a memory of at least 44 * SAA7146_I2C_MEM bytes size. if we exceed this limit... 45 */ 46 if ((4 * mem) > SAA7146_I2C_MEM) { 47 /* DEB_I2C("cannot prepare i2c-message\n"); */ 48 return -ENOMEM; 49 } 50 51 /* be careful: clear out the i2c-mem first */ 52 memset(op,0,sizeof(__le32)*mem); 53 54 /* loop through all messages */ 55 for(i = 0; i < num; i++) { 56 57 addr = i2c_8bit_addr_from_msg(&m[i]); 58 h1 = op_count/3; h2 = op_count%3; 59 op[h1] |= cpu_to_le32( (u8)addr << ((3-h2)*8)); 60 op[h1] |= cpu_to_le32(SAA7146_I2C_START << ((3-h2)*2)); 61 op_count++; 62 63 /* loop through all bytes of message i */ 64 for(j = 0; j < m[i].len; j++) { 65 /* insert the data bytes */ 66 h1 = op_count/3; h2 = op_count%3; 67 op[h1] |= cpu_to_le32( (u32)((u8)m[i].buf[j]) << ((3-h2)*8)); 68 op[h1] |= cpu_to_le32( SAA7146_I2C_CONT << ((3-h2)*2)); 69 op_count++; 70 } 71 72 } 73 74 /* have a look at the last byte inserted: 75 if it was: ...CONT change it to ...STOP */ 76 h1 = (op_count-1)/3; h2 = (op_count-1)%3; 77 if ( SAA7146_I2C_CONT == (0x3 & (le32_to_cpu(op[h1]) >> ((3-h2)*2))) ) { 78 op[h1] &= ~cpu_to_le32(0x2 << ((3-h2)*2)); 79 op[h1] |= cpu_to_le32(SAA7146_I2C_STOP << ((3-h2)*2)); 80 } 81 82 /* return the number of u32s to send */ 83 return mem; 84 } 85 86 /* this functions loops through all i2c-messages. normally, it should determine 87 which bytes were read through the adapter and write them back to the corresponding 88 i2c-message. but instead, we simply write back all bytes. 89 fixme: this could be improved. */ 90 static int saa7146_i2c_msg_cleanup(const struct i2c_msg *m, int num, __le32 *op) 91 { 92 int i, j; 93 int op_count = 0; 94 95 /* loop through all messages */ 96 for(i = 0; i < num; i++) { 97 98 op_count++; 99 100 /* loop through all bytes of message i */ 101 for(j = 0; j < m[i].len; j++) { 102 /* write back all bytes that could have been read */ 103 m[i].buf[j] = (le32_to_cpu(op[op_count/3]) >> ((3-(op_count%3))*8)); 104 op_count++; 105 } 106 } 107 108 return 0; 109 } 110 111 /* this functions resets the i2c-device and returns 0 if everything was fine, otherwise -1 */ 112 static int saa7146_i2c_reset(struct saa7146_dev *dev) 113 { 114 /* get current status */ 115 u32 status = saa7146_i2c_status(dev); 116 117 /* clear registers for sure */ 118 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 119 saa7146_write(dev, I2C_TRANSFER, 0); 120 121 /* check if any operation is still in progress */ 122 if ( 0 != ( status & SAA7146_I2C_BUSY) ) { 123 124 /* yes, kill ongoing operation */ 125 DEB_I2C("busy_state detected\n"); 126 127 /* set "ABORT-OPERATION"-bit (bit 7)*/ 128 saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07)); 129 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 130 msleep(SAA7146_I2C_DELAY); 131 132 /* clear all error-bits pending; this is needed because p.123, note 1 */ 133 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 134 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 135 msleep(SAA7146_I2C_DELAY); 136 } 137 138 /* check if any error is (still) present. (this can be necessary because p.123, note 1) */ 139 status = saa7146_i2c_status(dev); 140 141 if ( dev->i2c_bitrate != status ) { 142 143 DEB_I2C("error_state detected. status:0x%08x\n", status); 144 145 /* Repeat the abort operation. This seems to be necessary 146 after serious protocol errors caused by e.g. the SAA7740 */ 147 saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07)); 148 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 149 msleep(SAA7146_I2C_DELAY); 150 151 /* clear all error-bits pending */ 152 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 153 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 154 msleep(SAA7146_I2C_DELAY); 155 156 /* the data sheet says it might be necessary to clear the status 157 twice after an abort */ 158 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 159 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 160 msleep(SAA7146_I2C_DELAY); 161 } 162 163 /* if any error is still present, a fatal error has occurred ... */ 164 status = saa7146_i2c_status(dev); 165 if ( dev->i2c_bitrate != status ) { 166 DEB_I2C("fatal error. status:0x%08x\n", status); 167 return -1; 168 } 169 170 return 0; 171 } 172 173 /* this functions writes out the data-byte 'dword' to the i2c-device. 174 it returns 0 if ok, -1 if the transfer failed, -2 if the transfer 175 failed badly (e.g. address error) */ 176 static int saa7146_i2c_writeout(struct saa7146_dev *dev, __le32 *dword, int short_delay) 177 { 178 u32 status = 0, mc2 = 0; 179 int trial = 0; 180 unsigned long timeout; 181 182 /* write out i2c-command */ 183 DEB_I2C("before: 0x%08x (status: 0x%08x), %d\n", 184 *dword, saa7146_read(dev, I2C_STATUS), dev->i2c_op); 185 186 if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) { 187 188 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 189 saa7146_write(dev, I2C_TRANSFER, le32_to_cpu(*dword)); 190 191 dev->i2c_op = 1; 192 SAA7146_ISR_CLEAR(dev, MASK_16|MASK_17); 193 SAA7146_IER_ENABLE(dev, MASK_16|MASK_17); 194 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 195 196 timeout = HZ/100 + 1; /* 10ms */ 197 timeout = wait_event_interruptible_timeout(dev->i2c_wq, dev->i2c_op == 0, timeout); 198 if (timeout == -ERESTARTSYS || dev->i2c_op) { 199 SAA7146_IER_DISABLE(dev, MASK_16|MASK_17); 200 SAA7146_ISR_CLEAR(dev, MASK_16|MASK_17); 201 if (timeout == -ERESTARTSYS) 202 /* a signal arrived */ 203 return -ERESTARTSYS; 204 205 pr_warn("%s %s [irq]: timed out waiting for end of xfer\n", 206 dev->name, __func__); 207 return -EIO; 208 } 209 status = saa7146_read(dev, I2C_STATUS); 210 } else { 211 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 212 saa7146_write(dev, I2C_TRANSFER, le32_to_cpu(*dword)); 213 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 214 215 /* do not poll for i2c-status before upload is complete */ 216 timeout = jiffies + HZ/100 + 1; /* 10ms */ 217 while(1) { 218 mc2 = (saa7146_read(dev, MC2) & 0x1); 219 if( 0 != mc2 ) { 220 break; 221 } 222 if (time_after(jiffies,timeout)) { 223 pr_warn("%s %s: timed out waiting for MC2\n", 224 dev->name, __func__); 225 return -EIO; 226 } 227 } 228 /* wait until we get a transfer done or error */ 229 timeout = jiffies + HZ/100 + 1; /* 10ms */ 230 /* first read usually delivers bogus results... */ 231 saa7146_i2c_status(dev); 232 while(1) { 233 status = saa7146_i2c_status(dev); 234 if ((status & 0x3) != 1) 235 break; 236 if (time_after(jiffies,timeout)) { 237 /* this is normal when probing the bus 238 * (no answer from nonexisistant device...) 239 */ 240 pr_warn("%s %s [poll]: timed out waiting for end of xfer\n", 241 dev->name, __func__); 242 return -EIO; 243 } 244 if (++trial < 50 && short_delay) 245 udelay(10); 246 else 247 msleep(1); 248 } 249 } 250 251 /* give a detailed status report */ 252 if ( 0 != (status & (SAA7146_I2C_SPERR | SAA7146_I2C_APERR | 253 SAA7146_I2C_DTERR | SAA7146_I2C_DRERR | 254 SAA7146_I2C_AL | SAA7146_I2C_ERR | 255 SAA7146_I2C_BUSY)) ) { 256 257 if ( 0 == (status & SAA7146_I2C_ERR) || 258 0 == (status & SAA7146_I2C_BUSY) ) { 259 /* it may take some time until ERR goes high - ignore */ 260 DEB_I2C("unexpected i2c status %04x\n", status); 261 } 262 if( 0 != (status & SAA7146_I2C_SPERR) ) { 263 DEB_I2C("error due to invalid start/stop condition\n"); 264 } 265 if( 0 != (status & SAA7146_I2C_DTERR) ) { 266 DEB_I2C("error in data transmission\n"); 267 } 268 if( 0 != (status & SAA7146_I2C_DRERR) ) { 269 DEB_I2C("error when receiving data\n"); 270 } 271 if( 0 != (status & SAA7146_I2C_AL) ) { 272 DEB_I2C("error because arbitration lost\n"); 273 } 274 275 /* we handle address-errors here */ 276 if( 0 != (status & SAA7146_I2C_APERR) ) { 277 DEB_I2C("error in address phase\n"); 278 return -EREMOTEIO; 279 } 280 281 return -EIO; 282 } 283 284 /* read back data, just in case we were reading ... */ 285 *dword = cpu_to_le32(saa7146_read(dev, I2C_TRANSFER)); 286 287 DEB_I2C("after: 0x%08x\n", *dword); 288 return 0; 289 } 290 291 static int saa7146_i2c_transfer(struct saa7146_dev *dev, const struct i2c_msg *msgs, int num, int retries) 292 { 293 int i = 0, count = 0; 294 __le32 *buffer = dev->d_i2c.cpu_addr; 295 int err = 0; 296 int short_delay = 0; 297 298 if (mutex_lock_interruptible(&dev->i2c_lock)) 299 return -ERESTARTSYS; 300 301 for(i=0;i<num;i++) { 302 DEB_I2C("msg:%d/%d\n", i+1, num); 303 } 304 305 /* prepare the message(s), get number of u32s to transfer */ 306 count = saa7146_i2c_msg_prepare(msgs, num, buffer); 307 if ( 0 > count ) { 308 err = -EIO; 309 goto out; 310 } 311 312 if ( count > 3 || 0 != (SAA7146_I2C_SHORT_DELAY & dev->ext->flags) ) 313 short_delay = 1; 314 315 do { 316 /* reset the i2c-device if necessary */ 317 err = saa7146_i2c_reset(dev); 318 if ( 0 > err ) { 319 DEB_I2C("could not reset i2c-device\n"); 320 goto out; 321 } 322 323 /* write out the u32s one after another */ 324 for(i = 0; i < count; i++) { 325 err = saa7146_i2c_writeout(dev, &buffer[i], short_delay); 326 if ( 0 != err) { 327 /* this one is unsatisfying: some i2c slaves on some 328 dvb cards don't acknowledge correctly, so the saa7146 329 thinks that an address error occurred. in that case, the 330 transaction should be retrying, even if an address error 331 occurred. analog saa7146 based cards extensively rely on 332 i2c address probing, however, and address errors indicate that a 333 device is really *not* there. retrying in that case 334 increases the time the device needs to probe greatly, so 335 it should be avoided. So we bail out in irq mode after an 336 address error and trust the saa7146 address error detection. */ 337 if (-EREMOTEIO == err && 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) 338 goto out; 339 DEB_I2C("error while sending message(s). starting again\n"); 340 break; 341 } 342 } 343 if( 0 == err ) { 344 err = num; 345 break; 346 } 347 348 /* delay a bit before retrying */ 349 msleep(10); 350 351 } while (err != num && retries--); 352 353 /* quit if any error occurred */ 354 if (err != num) 355 goto out; 356 357 /* if any things had to be read, get the results */ 358 if ( 0 != saa7146_i2c_msg_cleanup(msgs, num, buffer)) { 359 DEB_I2C("could not cleanup i2c-message\n"); 360 err = -EIO; 361 goto out; 362 } 363 364 /* return the number of delivered messages */ 365 DEB_I2C("transmission successful. (msg:%d)\n", err); 366 out: 367 /* another bug in revision 0: the i2c-registers get uploaded randomly by other 368 uploads, so we better clear them out before continuing */ 369 if( 0 == dev->revision ) { 370 __le32 zero = 0; 371 saa7146_i2c_reset(dev); 372 if( 0 != saa7146_i2c_writeout(dev, &zero, short_delay)) { 373 pr_info("revision 0 error. this should never happen\n"); 374 } 375 } 376 377 mutex_unlock(&dev->i2c_lock); 378 return err; 379 } 380 381 /* utility functions */ 382 static int saa7146_i2c_xfer(struct i2c_adapter* adapter, struct i2c_msg *msg, int num) 383 { 384 struct v4l2_device *v4l2_dev = i2c_get_adapdata(adapter); 385 struct saa7146_dev *dev = to_saa7146_dev(v4l2_dev); 386 387 /* use helper function to transfer data */ 388 return saa7146_i2c_transfer(dev, msg, num, adapter->retries); 389 } 390 391 392 /*****************************************************************************/ 393 /* i2c-adapter helper functions */ 394 395 /* exported algorithm data */ 396 static const struct i2c_algorithm saa7146_algo = { 397 .master_xfer = saa7146_i2c_xfer, 398 .functionality = saa7146_i2c_func, 399 }; 400 401 int saa7146_i2c_adapter_prepare(struct saa7146_dev *dev, struct i2c_adapter *i2c_adapter, u32 bitrate) 402 { 403 DEB_EE("bitrate: 0x%08x\n", bitrate); 404 405 /* enable i2c-port pins */ 406 saa7146_write(dev, MC1, (MASK_08 | MASK_24)); 407 408 dev->i2c_bitrate = bitrate; 409 saa7146_i2c_reset(dev); 410 411 if (i2c_adapter) { 412 i2c_set_adapdata(i2c_adapter, &dev->v4l2_dev); 413 i2c_adapter->dev.parent = &dev->pci->dev; 414 i2c_adapter->algo = &saa7146_algo; 415 i2c_adapter->algo_data = NULL; 416 i2c_adapter->timeout = SAA7146_I2C_TIMEOUT; 417 i2c_adapter->retries = SAA7146_I2C_RETRIES; 418 } 419 420 return 0; 421 } 422